Trice: My age-defying Granny Smith apples

A thin coat of wax or oil is applied to most apples and helps prevent the loss of vitamins found largely in the skin. Washing them in hot water can help remove the treatments. (Chicago Tribune)

On my kitchen table is a stainless steel bowl of Granny Smith apples that are for show rather than consumption. I got the idea a few years ago from a display in a hotel lobby.

Although the apples, which are naturally hearty, sit on the table for days, even weeks, at a time, I do find it troubling that they remain so bright green, so shiny for so long. It used to be that when you left an apple out on the counter for a mere day or two, it would begin to rot and cave in on itself.

Not anymore. What's different about my age-defying Granny Smiths? I recently talked about food and fruit processing with Kantha Shelke, a scientist and spokeswoman for the Chicago-based Institute of Food Technologists. She also has a company that does research and product development work.

Most of us may think of processed foods in terms of boxed meals or snacks that have been zapped of nutrition and filled with preservatives and other chemicals to extend their shelf life. But, as you'll see from our conversation, that's not the entire story:

Trice: First, please define food or fruit processing.

Shelke: Let's say we pluck an apple from a tree. We wash it and wrap it up and place it in our purse. In some ways we've processed it. If we slice it, we've processed it one step more. The issue people have is not so much with the processing but the extent to which foods are subjected to it.

But some foods, such as grains, cannot be consumed if not processed. The issue is when you remove the bran and you mill it and strip it of vitamins and then you have to fortify it to try to put the vitamins back in. And you've made dough that you've extruded and puffed. It becomes cardboard and you have to add butter, sugar and salt so it doesn't taste like cardboard.

Trice: So, what's going on with my Granny apples?

Shelke: There's something called post-harvest technology. It's an interdisciplinary science that studies the best ways of preserving food by controlling or enhancing the quality, processing, packaging and storage of food.

Trice: Does that mean the type of technology that's used depends upon the particular fruit or vegetable that's being harvested?

Shelke: Exactly. It may take a village to raise a child, but it takes more than a village to raise an apple that's shiny and delicious and stays that way for five to seven days after harvesting. There's a lot going on, but the most important part has to do with the cooling.

Trice: Except for bananas, I keep the fresh produce we eat in the refrigerator. Is that what you mean?

Shelke: That cooling is not as important as cooling fruits and vegetables right after they're plucked. When our grandmothers harvested their food, they didn't cool them immediately and (the food) spoiled faster.

When you harvest an item, you pick it when it's at its peak of quality. There's a lot happening inside your apple. As it ripens, it's becoming softer and sweeter. It has a pleasant aroma and the vitamins and minerals are interacting. All of those things that make the item appealing also lead to its decline.

Once you pluck it, you have to find a way to stop or slow the decline, and mass producers know one of the best ways is to chill it.

Trice: How does chilling affect nutrition?

Shelke: The micronutrients continue to react during ripening, but when you chill an item, it stops that reaction. If you store the apple, for example, for an extended period, the vitamin C will diminish over time in the oxidation process.

And let me just say that we mentioned chilling, but there are other processes that extend the life of fruits and vegetables. Produce also needs to be treated gently. If it's not handled properly, it won't last.

The third thing it needs is moisture. Fruit and vegetables have a continuous moisture source when they're connected to a plant. But when you separate them from that source, the moisture will start to leave the skin. That's why produce handlers will put a thin wax or oil coating on some fruits and even vegetables such as eggplant. It's like when we moisturize our skin so that it stays plump longer.

Trice: But when I cut into my pretty and plump Granny Smiths, they're a scary mess on the inside.

Shelke: That's correct, the process of decaying continues.

Trice: Does the wax affect nutrition?

Shelke: Because most of the vitamins are in the skin, the coating offers some protection for the vitamins but eventually they get oxidized too.

Trice: But the wax scares me.

Shelke: My answer for that is to wash it in hot water.

Trice: What about organic fruits and veggies?

Shelke: Most apples are subjected to pesticides to keep the pests out. There used to be a time when you'd find a worm in your apple. But I don't think the younger generation has ever seen a worm in an apple. Organic means only certain pesticides can be used. It doesn't necessarily mean absolutely no pesticides were used.

Trice: What are your thoughts about genetically modified fruits and veggies?